Demountable rock bit



Dec. 12,1939.

J. T. PHIPPS DEMOUNTABLE ROCK BIT Filed Dec. 19, 1958 2 Sheets-Sheet 1 Patented Dec. 12, 1939 UNITED STATES DEMOUNTABLE noon BIT John T. Phipps, Huntington Park, Calif., assignor to W. K. P. Oil Tool 00., a corporation of California Application December 19, 1938, Serial No. 246,643

21 Claims.

This invention relates to roller bits for use in rotary drilling, and has as a broad object to provide a roller bit construction which can be readily disassembled and reassembled to permit 5 repair or replacement of the wearing parts.

Another object is to provide a roller bit that is exceptionally strong and rigid and has large bearing surfaces for rotatably supporting the cutting rollers.

Another object is to provide a roller bit hav- 1,

ing a cross cutter roller assembly adapted to be preassembled as a unit, and inserted and removed from the bit as a unit.

Other minor objects and features 0 he inven- 15 tion, and the manner in which they, together with the foregoing objects, are achieved, will now be explained by describing in detail, with reference to the drawing, a specific embodiment of the invention. 20 This is in part a continuation of my application Serial No. 165,910, filed September 27, 1937 on Roller bits, now Patent Number 2,145,573, granted January 31, 1939. In the drawings: 7 Fig. 1 is a side elevational view of a roller bit'in accordance with the invention;

Fig. 2 is a vertical section through the bit, taken substantially in the plane of the axis of the cross cutting rollers; 30 r Fig. 3 is a vertical section similar to Fig. 2, but illustrating another embodiment of the invention; Fig. 4 is a vertical section similar to Fig. 2, but illustrating still another embodiment of the invention: 35 Fig. 5 is a detail horizontal view, taken in the plane V--V of Fig. 4; and

Fig. 6 is a vertical sectional view showing the construction of one of the side cutting rollers. Referring first to Figs. 1 and 2, the roller bit 40 therein disclosed comprises a body member vI having a threaded stub 2 on the upper end thereof for attachment to-a drill shaft and having four downwardly depending arms 3, 4,5 and 6 thereon for supporting cutting rollers, arms 3 45 and 4 being juxtaposed to each other in spaced apart relation, and arms 5 and 6 being likewise in juxtaposed spaced apart relation relative to each other and displaced 90 about the body I from the arms 3 and 4, respectively. The arms 50 3 and 4 support a main cutting roller assembly,

constituting the present invention, and the arms 5 and 6 support auxiliary outer, inclined, side cutting rollers in accordance with the usual practice, one of these auxiliary cutting rollers 40 55 being shown in Fig. 1.

Referring now to Fig. 2, arms 3 and 4, respectively, have inwardly extending stub shafts l and 8, respectively, thereon which may be welded to the arms 3 and 4, respectively, and each stub shaft has an aperture extending therethrough, 5

the aperture 9 in the stub shaft 1 being in alignment with the aperture I in the stub shaft 8" and'both of these apertures being centrally disposed with respect to the outer surfaces of the stub shafts. A main pin orcross shaft H ex- 10 tends. through and is fitted in the apertures 8 and I0 and supports a bushing l2 positioned between the inner ends of the stub shafts I and 8, respectively. Positioned in alignment between the arms 3 and 4 are four cutting rollers I3, I4, I5 and I6, respectively. The cutting roller I3 is rotatably supported by rollers I1 and balls l8 on a bearing member l9, which is threaded to screw onto the stub shaft 1, the outer surface of the latter being threaded to receive the member IS. The cutting rollers l4 and I5 are rotatably mounted on hearing rollers 20 and 2|, respectively, directly on the bushing l2. Cutting rollers l4 and I5 are separated longitudinally by a flange 22 on bushing l2, this flange 22 having its outer 25 periphery cut in polygonal shape, or having teeth out in its periphery, to permit engagement by a tool for turning the same during assembly and disassembly, as will be described later.

The cutting roller I6 is rotatably supported by bearing rollers 23 and balls 24 on a bearing member 25, which is threaded to screw onto the stub shaft 8. r

When the structure described is assembled,

the pin ll is-solidly locked in the apertures 8 and l 0 against any movement with respect to the arms 3 and 4, the bushing 22 is solidly locked against movement with respect to the pin H, and the bearing bushings l9 and 25 are firmly locked against movement on the stub shafts 1 40 and 8, respectively.

I secure these results in a demountable structure as follows:

The pin II is rigidly fixed in the aperture l0 in stub shaft 8 by tapering the latter aperture from a large diameter at the, outer end to a smaller diameter at the inner end thereof and correspondingly tapering the end portion of pin ll so that when the shaft is drawn to the left 5 (as shown in Fig. 2) it wedges firmly in the aperture III in stub shaft 8. I further prevent any possible rotation of pin ll after it has been placed in position by providing a pin 21 in the end thereof, the end of the pin projecting from the of the aperture 9 when the screw plug 29 is screwed into the counterbore.

To lock the bushing I2 against movement with respect to the pin II, the latter is provided with threads 32 which engage with cooperating threads on the inner surface of the bushing I2 at the right end thereof. By applying a. suitable wrench to the flange 22 on bushing I2, the bushing can be screwed tightly onto the threaded portion .32 of pin II, clamping the right end of bushing I2 flrmly against the inner end of the bearing member on the stub shaft 8 on arm 4, and thereby preventing any possible movement, in operation,

of the bushing-I2.

The inner ends of the bearing members I 9 and 25 are provided with radial slots 34 and 35, re.- spectively, adapted to receive a suitable wrench for turning the bearing members during assembly and disassembly.

The roller elements described with reference to Fig. 2 are assembled as follows: First the hearing member I0, carrying the bearing rollers I1, the bearing balls, I8 and the cutting roller I3,is screwed onto thestub shaft 1, and the assembly comprising the cutting rollers I5, bearing rollers 23, bearing balls 24 and bearing member 25 are placed in position by screwing the bearing member 25 onto the shaft 8. These operations are performed while the pin II, bushing I2 and the cutting roller elements supported thereon are removed. Then the assembly of the bushing I2, bearing rollers 29, cutting roller I4 and the bearing rollers 2| and cutting roller I5 is slid into position between the juxtaposed ends of the cutting rollers I3 and I6. Then the pin II is inserted through the aperture I0 and the bushing I2 until the threads 32 thereon abut against the ends of the threads in bushing I2, after which the bushing I2 is rotated, by means of a suitable wrench applied to the flange 22, to screw the threaded portion of bushing I2 onto the threads 32 of pin II, this screwing action drawing the pin II from right to left until it is seated solidlyin the aperture l9 and the bushing l2 is drawn up tight against the bearing'member 25. 'The pin II is then firmly locked in the aperture 9 by inserting the screw plug 29 and screw-. ing it up tight. While turning force is being applied to the plug 29 the outer face of the arm 3 may be struck with a hammer to move the arm in until the inner end of the bearing member I9 presses tightly againstithe end of the bushing I2, the arm 3 being secured in such inner position because of the left end of the pin II being expanded outwardly against the tapered end portion of the aperture 9 by the plug 29. The structure shown in Fig. 2 may be disassembled by -merely reversing the operation described; that is, first'removing the plug 29, then rotating the bushing I2 to disengage the threaded portion thereof'from the threads 32 on the pin II, this action automatically moving the pin to the right out of tight engagement with the stub shaft 8, completely removing the pin II, then removing .arms,

the bushing I2, and the elements supported thereon, and finally removing the bearing bushings I9 and 25 and the cutting rollers assembled thereon.

The modification shown in Fig. 3 differs from Fig. 2 in that all of the cutting rollers are mounted on a unitary bushing which may be inserted or removed as a unit from the bit, and in the use of a slightly different expanding belt or plug on the end of the main cross shaft. Thus the structure of Fig. 3 comprises a body member I having downwardly depending juxtaposed arms 3' and 4' for supporting the cross cutter roller assembly. Arms 3' and 4 are provided with aligned apertures 59 and 5|, respectively, each of which is flared from a small diameter to a larger diameter at the outer surface of the associated arm.- These apertures 50 and 5I receive and support a main pin 52 which is provided with an outwardly flaring head 53 at one end and adapted to seat in the flared aperture 5I and is provided at the other 'end with segments 54 adapted to be forced outwardly into locking engagement with the flared aperture 50 by the head of a bolt 55 screwed into a threaded recess in the end of pin 52.

The pin 52 supports a bushing composed of two sections 55 and 51, respectively, which bushings are adapted to be interengaged to each other by means of an externally threaded extension 58 on section 51 which screws into a threaded recess provided in the end of bushing section 55. Bushing section 51 is internally threaded adjacent its outer end to receive external threads 59 on the pin 52. To prevent rotation of the bushing sections with respect to the arms 3' and 4 a lock screw 55 is threaded into each of the each screw being adapted to fit in one of a plurality of recesses 5| positioned in the outer ends of the bushing sections 55 and 51, respectively, and symmetrically spaced about the axes of the bushings.

In the particular construction shown in Fig. 3, four cutting rollers 53, 54, and 55 are mounted on the bushing between the arms 3' and 4'. Cutting roller 53 is supported on the bushing section 55 by roller bearings 19 and ball bearings 1 I. The cutting rollers 54 and 55 are mounted on the bushing section 55 by roller bearings 12 and 13, respectively, and the cutting roller 55 is mounted on the bushing section 51 by a roller bearing 14 and a ball bearing 15.

The structure described with reference to Fig. 3 is very strong and rigid. in operation because the pin 52 is held solidly within the arms 3' and 4 and by virtue of the extensible end segments 54 on the left end of the shaft and the flared head 53 on the other end, the two arms 3' and 4' are drawn tightly against the ends of the bushing, preventing any longitudinal motion thereof. The bushing is further retained against any longitudinal motion by the threads 59 on the pin 52. Any rotation of the bushingis not only resisted by the friction between the ends of the bushing and the arms 3' and 4 and the threads 59 on the pin 52, but is further positively prevented by the set screws 50 which engage in the apertures 5| in the opposite ends of the bushing.

However, when desired, the cutting roller can be very easily and quickly removed and replaced by a new assembly consisting of a new bushing having all four new cutters preassembled thereon. Thus to disassemble the structure shown in Fig. 3, the lock bolt 55 is first removed from the end of the pin 52 and then the shaft withdrawn by inserting a screw-driver in the .slotted head thereon and rotating the screw to the left, causing the threads 59 on the shaft to screw out of the bushing sec tion 51, thereby forcing the shaft to the right and contracting the segments 54 in the left end there'- of, so that they can pass through the aperture ill.

By the time the threaded portion 59 of the shaft is disengaged from the threads in the bushing sec tion 51 the head 53 of the shaft can be grasped with any suitable tool and completely withdrawn.

The lock screws 60 are next partially orcompletely -withdrawn, whereupon the entire assembly, in-' cluding the bushing sections 56 and 5'land the cutting rollers rotatably mounted thereon, can be dropped out from between the arms 3' and 4'. Assembly of a new. roller assembly is performed in reverse'manner. Thusthe assembly is inserted between the arms 3' and 4' of the shaft 52 partLv inserted to support the cutter assembly. The

so bushing is then rotated to bring apertures ii in alignment with the lock screws 60 and the latter set up. The pin 52 is then screwed home and locked in place by inserting the lock screw 55 in the end thereof.

88 Each bushing bearing roller and cutter roller' assembly may be disassembled after removal from the drill by unscrewing the two bushing sections ployed. Thus referring to Fig. 4, the bit therein depicted comprises. a body member I" having downwardly depending juxtaposed armsv 3" and 4", which arms are'provided near their lower ends with a pair of juxtaposed apertures and II, respectively, for receiving a main cross pin l2. Both of the apertures 80 and 8| are tapered or flared so that their outer orifices are of larger diameter than their inner orifices and'one end of the pin 82 is correspondingly tapered to fit snugly within the aperture ll. 82 is divided into segments "adapted to be expanded radially outwardly into snug engagement with the tapered aperture 80.

To expand the segments 84, the pin 82 is made hollow to receive a rivet 85 which extends therethrough fr5m one end tothe other. The rivet II' has a tapered head 86 on one end which is driveninto the shaft and bears against and expands the as segments to fit tightly in the aperture 8!. The rivet 85 is retained inset position by ,upsetting its oppo te end l-I so that it expands to fill a flared seat .8 in the right end of the pin 82.

a pair of cutting rollers so, both of which are no identical and identically mounted, are supported on the pin 82. Thus each cutting roller 9| is radially supported for free rotation on the pin .2-

. by two sets of roilerbearings ii and 92. axial thrust of each cutting roller 90 is taken by a row of ball bearings 93 positionedbetween a race 84 formed in the cutting roller and a race by the pin 82.

70 drical aperture ther movement by the shaft. Each block 9 is supported against rdtary movement by the-adjacent arm 3" or 4''.

it Thus referring toFig. 5, the m. as is pro- The opposite end of pin v'idedwith a pair of tenons I! which fitin a groove it in the inner face ofthe associated arm.

The structure of Fig. 4 is assembled and disassembled as follows: n

Each of the cutting rollers OI, its associa roller bearings SI and 92, 'ball bearings 33 and block "is moved into position adjacent one of the arms 3" or 4" by sliding the tenon 91 on the block Ii upwardly in the groove 9|. The assembly, including the other cutting roller 90, roller bearings 92 and 93 and block 86, is similarly inserted. Then the cross pin 82 is inserted first through aperture ll, then through the two roller assemblies, and into the aperture ll, being driven into position with the'enlarged right end fitting snugly into the flared aperture II. The rivet I5 is then inserted in the pin 82v from left to right and drawn up tightly by hammering it on the head 86 to spread the segments ll tightly against the wall of the aperture ill and hammering it on theopposite end .to upset the latter and form the head 81 to retain the rivet. in

- position.

The bit may be disassembled by first driving out the rivet "from right to left, the upset right end being drawn out in the process, and then removing the pin 82, after which the cutting roller assemblies may be slid out of the body.

The structure for supporting the side cutting rollers II is illustrated in Fig 6. Thus there is attached to thearm 5, as by welding,-a downwardly andinwardly extending stub shaft I00 having a threaded end portion IIII and a threaded shoulder I02, which is of larger diameter and positioned back of the threaded-end portion IN.

The shoulder I02 receives an internally threaded bearing member I03, which is screwed tightly thereon, this bearing member forming an inner race for radial roller bearings II", and half of. the inner race forball thrust bearings 105. To complete the inner race for the ball bearings I I! a second internally threaded bearing member II is screwed onto the outer threaded portionill of the shaft I Ill. This member III forms one-half of the inner-race to receive balls I05 and is locked in position after assembly. To this end, the internal diameter of the threaded opening in member I is larger at the outer end than at the inner end, and the end portion of the shaft III is slotted to form segments I01 which can be expanded outwardly intotight engagement with threaded member III. These seg-.. 'ments I" are expanded after assembly in the same manner as the segments 8 on the cross shaft are expanded; namely, by means of a tapered rivet. This rivet III extends through a central passage inthe shaft I" and is provided with a head If on-its inner end which expands the segments I" when the rivet is drawn up tight as by driving the heads II! and upsetting the outer end Ill to retain the rivet in,position.

The radial roller hearing I" and the thrust ball bearing II! rotatably support the side cut-' ting roller ll directly, as shown in Fig. 6, the

roller being provided with suitable races to bear against the rollers IN and balls I05.

Although the invention has been explained by \V describing in detail a specific embodiment there of, it is to be understood that various changes can bemade from the specific structure shown, without departing from the invention, ',and the latter is to! limited only to the extent set forth --in the appended claims.

I claim: e a l 1. A roller bit,comprising a frame member 78 having a pair of spaced-apart supporting members, a shaft supported by and extending between said supporting members, a sleeve non-rotatably supported on said shaft between said supporting members, and cutting roller means rotatably supported on said sleeve.

2. A roller bit comprising a frame member having a pair of spaced-apart supporting members having aligned apertures therein, a shaft extending through said apertures and supported by said supporting members at its opposite ends, means for releasably anchoring the ends of said shaft rigidly to said supporting members, a bearing member on said shaft between said supporting members, means for releasably anchoring said bearing member rigidly to said shaft, and cutting roller means rotatably suported on said bearing means.

3. A roller bit comprising a frame member having a pair of spaced-apart downwardly depending arms in juxtaposed relation, said arms having aligned apertures therein, a pin extending through said apertures and supported by said arms at its opposite ends, a bushing means mounted on said pin between said arms, means for limiting inward movement of one end' of said pin with respect to the adjacent arm, and means for releasably expanding the opposite end of said pin, the aperture in the arm receiving said opposite end of said pin being of larger diameter at its outer end than at its inner end and cutting roller means rotatably supp r on said bushing means.

4. A roller bit comprising a frame member having a pair of spaced-apart downwardly depending arms in juxtaposed relation, said arms having aligned apertures therein, .a pin extending through said apertures and supported by said I arms at its opposite ends, said pin having a threaded portion intermediate said arms, a bushing mounted on said pin between said arms and having internal screw threads engaging the threads on said pin, and cutting roller meansrotatably mounted on said bushing.

5. A roller bit comprising a frame member having a pair of spaced-apart downwardly. de-

pending arms in juxtaposed relation, said arms having aligned apertures therein, a pin extending through said apertures and supported by said arms at its opposite ends, said pin having a threaded portion intermediatesaid arms, a bushing mounted on said pin between said arms and having internal screw threads for engaging the threads on said pin, means for limiting inward movement of one end of said pin with respect to the adjacent arm, means for releasably expanding the opposite end of said pin, the aperture in the arm receivlng'said opposite end of said pin being of larger diameter at its outer end than at its inner end.

6. A roller bit as described in claim 4, in which said bushing has wrench-engaging means thereon.accessible from theexterior of the assembled bit, whereby said bushing can be turned after assembly of the cutting roller means thereon to tighten or loosen the threaded connection between the pin and bushing.

7. A roller bit as described in claim 4, in which said bushing has wrench-engaging means thereon accessible from the exterior, whereby it can be turned after assembly of the cutting roller means thereon to tighten or loosen the threaded connection between the pin and bushing, and cooperating means on said pin and one at least of said arms for preventing rotation of the pin with respect to the arms.

8. A roller bit as described in claim 4, in which said aperture in one of said arms is larger at its outer end than at its inner end and the corresponding end of said pin is tapered to wedge into said aperture in response to relative rotation between said threaded bushing and said pin with the end of the bushing bearing against the inner face of said am. y

9. A roller bit as described in claim 3, in which said opposite end of said pin is split into segments, counterbored and threaded, and athreaded plug screwed into said counterbore for expanding the end of the pin into tight engagement with the aperture in said arm. 7

10. A roller bit as described in claim 3 in which said bushing means fills the space between said arms and is gripped between said .arms in response to expansion of said'opposite end of said pin. Y

11. A roller bit as described in claim 3, in which said opposite end of said pin is provided with a large counterbore and a smaller threaded counterbore extending 'into the pin from the bottom of the large counterbore, the portion of the pin surrounding the large counterbore being split into segments, and a bolt adapted to be screwed into said threadedcounterbore and having a head for bearing against and expanding said segments outwardly in the aperture in the associated arm.

12. A roller bit comprising a frame member having a pair of spaced-apart arms with inwardly extending stub shafts on said arms, said stub shafts having concentrically aligned apertures therein, a shaft extending through said-apertures and supported by said stub shafts at its opposite ends, bearing members on said stub shafts, cutting roller means rotatably supported on said bearing members, a stationary bearingmember on said shaft between said stub shafts, cutting roller means rotatably supported on said last mentioned bearing members, and means for releasably anchoring said first mentioned bearing members on said stub shafts and said last mentioned bearing member on said shaft.

13. A roller bit comprising a frame member having a pair of spaced-apart downwardly depending arms in juxtaposed relation, said arms having aligned apertures therein and having inwardly extending stub shafts concentrically positioned with respect to said apertures, a pin extending through-said apertures and supported by said arms at its opposite ends, a bushing mounted on said pin between the inner ends of said stub shafts, cutting roller means rotatably mounted on said bushing, cutting rollers on said stub shafts, and bearing means for rotatably mounting said cutting rollers on said stub shafts.

14. A roller bit as describedin claim 13, in which said bearing means for rotatably mounting said cutting rollers on said stub shafts comprise stationary bearing members. fitted on said two stub shafts, and means including said bushing aiaaaos by said supporting members attits opposite ends, means for releasably anchoring said shaft to said supporting members, a sleeve member on said shaft comprising two sections screwed together, releasable locking means for independently locking each of said members against rotation with respect to said spaced-apart supporting memtions of said sleeve member beinginterconnected between said enlarged portions thereof, whereby said cutting rollers may be disassembled from said sleeves following disassembly thereof.

18. In a roller bit, a hollow shaft, 8. member enslots therein dividing it into segments and means expanding said segments into locking relation with said member, comprising a rod member extending through said hollow shaft and'having a tapered head within said segments, and means on the opposite end of said rod member engaging the adjacent end of said shaft for maintaining the tapered end of said rod member in expanding relation with said segments.

19. In a roller bit, a hollow shaft, a member encircling oneend of said shaft, said end having slots therein dividing it into segments and meansexpanding said segments into locking relation with said member, comprising a rivet extending through said hollowshaft from. end to end and having a tapered head within said segments, the

opposite end of said rivet being upset whereby it engages the adiacent end of the shaft for maintaining the tapered end of saidrivet in expanding relation with said segments.

20..A r01ler bit comprising a frame member 1 having a pair of spaced-apart supporting members, a hollow shaft supported by and extending betweeni said supporting members, cutting roller means rotatabiy supported on said shaft between said supporting members, said shaft extending into and being supported in tapered apertures in said supporting members, one 'end of said shaft having a tapered head thereon for engaging in one of said tapered apertures and the other end being segmented; and a rod member extending through said hollow shaft and having a tapered ,head within said segments for expanding the same against the walls of the aperture in the associated supporting member, and means on the opposite end of said rod member engaging the adjacent end of said shaft for maintaining the tapered end of said rod member in expanded relation with said segments. circling one end of said shaft, said end having a 21. A roller bit comprising-a fraine member supported thereby, and cooperating means on one of said supporting members and said stationary member for preventing rotation of said stationary member; said cooperating means comprising cooperating guide means on said supporting member and on said stationary member,

respectively, said guide means guiding said stationary member for linear motion only in a predetermined path radial with respect to said shaft.

' JOHN '1'. PEIIPPS. 

